MAHOUT-1466 Cluster visualization fails to execute

git-svn-id: https://svn.apache.org/repos/asf/mahout/trunk@1578543 13f79535-47bb-0310-9956-ffa450edef68
MAHOUT-1346: better PCA test & input generator

git-svn-id: https://svn.apache.org/repos/asf/mahout/trunk@1578663 13f79535-47bb-0310-9956-ffa450edef68